Controlled chemical degradation of natural rubber using periodic acid: Application for recycling waste tyre rubber

2012 ◽  
Vol 97 (5) ◽  
pp. 816-828 ◽  
Author(s):  
Faten Sadaka ◽  
Irène Campistron ◽  
Albert Laguerre ◽  
Jean-François Pilard
Keyword(s):  
Natural Rubber ◽  
Periodic Acid ◽  
Chemical Degradation ◽  
Waste Tyre

Chemical degradation of epoxidized natural rubber using periodic acid: Preparation of epoxidized liquid natural rubber

2004 ◽  
Vol 95 (1) ◽  
pp. 6-15 ◽  
Author(s):  
P. Phinyocheep ◽  
C. W. Phetphaisit ◽  
D. Derouet ◽  
I. Campistron ◽  
J. C. Brosse
Keyword(s):  
Natural Rubber ◽  
Periodic Acid ◽  
Chemical Degradation ◽  
Epoxidized Natural Rubber ◽  
Liquid Natural Rubber

Preparation and characterisation of liquid epoxidised natural rubber in latex stage by chemical degradation

2021 ◽  
Author(s):  
Nurul Hayati Yusof ◽  
Dazylah Darji ◽  
Fatimah Rubaizah Mohd Rasdi ◽  
Krishna Veni Baratha Nesan
Keyword(s):  
Natural Rubber ◽  
Chemical Degradation

Ultimate Tensile Properties of Elastomers. II. Comparison of Failure Envelopes for Unfilled Vulcanizates

1964 ◽  
Vol 37 (4) ◽  
pp. 792-807 ◽  
Author(s):  
Thor L. Smith
Keyword(s):  
Natural Rubber ◽  
Elevated Temperatures ◽  
Cross Sectional Area ◽  
Chemical Degradation ◽  
Sectional Area ◽  
Failure Envelope ◽  
Cross Sectional ◽  
Failure Envelopes ◽  
The Moment ◽  
Styrene Butadiene

Abstract The tensile stress-at-break σb (based on the initial cross-sectional area) and the corresponding ultimate extension ratio λb of unfilled vulcanizates of silicone, hydrofluorocarbon (Viton B), butyl (both sulfur-cured and resin-cured), and natural rubber were determined at many strain rates and temperatures; the latter ranged from slightly above the glass transition temperature Tg, up to a temperature somewhat below that at which chemical degradation affected the results. For each vulcanizate except natural rubber, data obtained over an extended temperature range superposed to give a time- and temperature-independent failure envelope on a plot of log (σb273/T) vs log (λb−1), where T is the test temperature in °K; for natural rubber, data obtained between 90° and 120° C superposed, but those at lower temperatures did not because of strain-induced crystallization. For each vulcanizate, data at elevated temperatures gave, or tended toward, a line of unit slope on a plot of log (λbσb273/T) vs log (λb−1), where λbσb is the breaking stress based on the cross-sectional area at the moment of rupture. The position of each line corresponded to the equilibrium modulus Ee derived from stress-strain curves. Failure envelopes previously obtained for two styrene—butadiene vulcanizates, which had different crosslink densities, superposed to give a master failure envelope on a plot of log (λbσb273/T) vs logEe(λb−1). On this type of plot, failure envelopes for all the vulcanizates except silicone and natural rubber were found to be essentially identical. At a given value of λbσb, silicone had a smaller λbλb and natural rubber a somewhat larger λbλb than the vulcanizates of the three other rubbery polymers.

Preparation of liquid epoxidized natural rubber in latex stage by chemical degradation

2018 ◽  
Author(s):  
Nurul Hayati Yusof ◽  
Dazylah Darji ◽  
Krishna Veni Baratha Nesan ◽  
Fatimah Rubaizah Mohd Rasdi
Keyword(s):  
Natural Rubber ◽  
Chemical Degradation ◽  
Epoxidized Natural Rubber

Property Enhancement of Silica-Filled Natural Rubber Compatibilized with Epoxidized Low Molecular Weight Rubber by Extra Sulfur

2013 ◽  
Vol 844 ◽  
pp. 235-238 ◽  
Author(s):  
Prachid Saramolee ◽  
Kannika Sahakaro ◽  
Natinee Lopattananon ◽  
Wilma Dierkes ◽  
Jacques W.M. Noordermeer
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Network Formation ◽  
Periodic Acid ◽  
Low Molecular Weight ◽  
Molecular Weight Range ◽  
Small Influence ◽  
Silane Molecule ◽  
Mooney Viscosity

The properties of both compounds and vulcanizates of silica-filled natural rubber (NR) compatibilized with epoxidized low molecular weight natural rubbers (ELMWNRs) consisting of 12 and 28 mol% epoxide are investigated. The ELMWNRs with a molecular weight range of 50,000 to 60,000 g/mol are produced by depolymerization of epoxidized natural rubber (ENR) latex using periodic acid, and then used as compatibilizer in a range of 0 to 15 phr in virgin NR. The compounds with LMWNR without epoxide groups, and with bis-(triethoxysilylpropyl) tetrasulfide (TESPT) coupling agent are also prepared for comparison purpose. Incorporation of ELMWNRs lowers Mooney viscosity and Payne effect to the level closed to that of silica/TESPT compound, and clearly enhances the modulus and tensile strength of vulcanizates compared to the compounds with no compatibilizer and LMWNR. The higher epoxide groups content results in the better tensile properties but somewhat less than the compound with TESPT. Addition of extra sulfur into the compounds with LMWNR and ELMWNRs to compensate for the sulfur released from silane molecule in the silica/TESPT system shows small influence on Mooney viscosity, but remarkably enhances 300% modulus, tensile strength and loss tangent at 60°C as a result of the better network formation.

CHEMICAL DEGRADATION OF POLYURETHANE FOAM WASTE AND ITS CROSSLINKED NATURAL RUBBER

2015 ◽  
Vol 88 (3) ◽  
pp. 437-448 ◽  
Author(s):  
Sa-Ad Riyajan ◽  
Nattanan Keawmwnee ◽  
Pramuan Tangboriboonrat
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Polyurethane Foam ◽  
Cost Effective ◽  
Chemical Degradation ◽  
Cure Rate ◽  
Elongation At Break ◽  
Environmental Friendly ◽  
Roll Mill ◽  
By Products

ABSTRACT The objective of this work was to use by-products from the chemical degradation of polyurethane foam waste (w-PUfd) and blend them with an epoxidized natural rubber (ENR), named PENR, for improving the mechanical properties of a Standard Thai rubber 5L (STR 5L). The swelling ratio in toluene of the PENR decreased as a function of w-PUfd content due to an increase in chemical interactions. After blending the PENR with the STR-5L and vulcanizing agents using two-roll mill and then compression molding at 150 °C, the effects of w-PUfd content in PENR on the properties of cured STR-5L were investigated. The cure rate index, tensile strength, and elongation at break of the cured STR-5L were improved after the addition of PENR. The swelling in toluene of cured STR-5L decreased as a function of w-PUfd in PENR. At 100 phr w-PUfd in PENR, the 20:80 PENR:STR-5L provided the highest tensile strength of ~23 MPa. These biodegradable, cured rubbers with w-PUfd content are environmental friendly and cost-effective products.

Silica-Reinforced Natural Rubber with Epoxidized Low Molecular Weight Rubber as a Compatibilizer

2013 ◽  
Vol 747 ◽  
pp. 522-525 ◽  
Author(s):  
Prachid Saramolee ◽  
Kannika Sahakaro ◽  
Natinee Lopattananon ◽  
Wilma Dierkes ◽  
Jacques W.M. Noordermeer
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Glass Transition ◽  
Natural Rubber ◽  
Periodic Acid ◽  
Dynamic Mechanical Properties ◽  
Low Molecular Weight ◽  
Service Temperature ◽  
Dynamic Mechanical ◽  
Tan Δ

This work investigates the effect of epoxidized low molecular weight natural rubber (ELMWNR) in silica-filled NR compounds on processing, mechanical and dynamic mechanical properties. The ELMWNRs with mol% epoxide groups varying from 0-50 and molecular weight in a range of 50,000-60,000 g/mol were prepared from depolymerization of epoxidized natural rubber using periodic acid in latex state. They were then added in the silica-filled NR compounds as a compatibilizer at varying loading from 0-15 phr. The addition of ELMWNR decreases compound viscosity and Payne effect, i.e. filler-filler interaction. The optimal mechanical properties of silica-filled vulcanizates are observed at the ELMWNR-28 (28 mol% epoxide) loading of 10 phr. The incorporation of ELMWNR with 28 and 51 mol% epoxide groups into NR compounds introduces a second glass transition temperature and affects on their dynamic mechanical properties. Higher epoxide content leads to higher Tan δ of the rubber vulcanizates in the range of normal service temperature.

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